12th International AIDS Conference Geneva, Switzerland - June 28-July 3, 1998

Int Conf AIDS 1998 Jun 28-Jul 3; 12:15 (abstract no. 11165)

Saksena N, Ge YC, Hira S, Gharpure H, Bolton W
Retroviral Genetics Lab WIHR CVR, Westmead Hospital, NSW, Australia.

OBJECTIVES: To molecularly and phylogenetically analyze HIV-1 strains from HIV-1 + HIV-2 coinfected individuals in India.

DESIGN: Molecular study of HIV-1 and HIV-2 coinfections in India. Apart from Thailand, India is the second country hardest hit by HIV epidemic, and is also unique in showing an efficient spread of HIV-1 and HIV-2 coinfections in about 3% of infected population in Western India. In addition, India has 4 different HIV-1 subtypes (A, E, B and C) and one HIV-2 subtype (A).

METHODS: In the present study we have carried-out a detailed molecular analysis of 24 patients recently infected between 1996-1997. Two of these 24 patients were co-infected with HIV-1 and HIV-2, 3 with HIV-2 alone and 19 with HIV-1 as seen by double ELISA and Western blot assays. Proviral DNA was amplified from PBMCs of HIV-1 and HIV-1 + HIV-2 infected patients in the env gp120 gene of HIV-1. The PCR fragments were sequenced directly, and phylogenetic analysis was carried out using neighbor joining and maximum parsimony methods.

RESULTS: Previous work suggests that the HIV-1/HIV-2 coinfections in 1994 were with HIV-1 subtype C and HIV-2 subtype A. Our molecular and phylogenetic analysis of the envelope gene provides a compelling evidence in favour of an epidemiologic shift in HIV-1 HIV-2 coinfections suggesting the recent coinfections to consist of HIV-2 subtype A, and highly novel and unique HIV-1 strains which have not been seen in HIV database at Los Alamos. More importantly, the most interesting feature of these HIV-1 strains from coinfected patients in India is their highly unstable phylogenetic position, along with the presence of large genomic areas in the envelope gene which are 58% homologous to all other HIV-1 strains recorded in Los Alamos HIV database. Since 58% homology is equivalent to the similarity between HIV-1 and HIV-2, we compared these HIV-1 strains with all known HIV-2 strains. Our detailed molecular comparisons suggest that these highly divergent forms of HIV-1 strains may form a distinct group of HIV-1 strains previously unseen, and they may be recombined forms resulting from recombination between HIV-1 and HIV-2.

CONCLUSIONS: These are the first data reporting the highly novel and previously unseen HIV-1 strains from HIV-1 + HIV-2 infected patients from India. The spread of such strains may pose the biggest risk of the Asia-pacific region.

Copyright © 1998 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.